Razor



A ril 6 1926. 1,579,577

R. E. THOMPSON RAZOR Filed June 4, 1924 M1. 21 v mp,

a; 2. WW.

Patented Apr. 6,1926.

- UNITED STATES PATENT OFFICE.

RALPH E. THOMPSON,

DELAWARE.

Application filed June 4,

To all whom it may concern:

.\ a citizen of the United States, residing at Brookline, in the count of Norfolk and State of Massachusetts, ave invented certain new and useful Improvements in Razors, of which the following is a specification.

The ob'eet of my invention is to provide va razor lade having a ,safety edge, by which I mean an edge which is self-protected in such manner as to prevent it from cutting the skin without materially impairing its efi'ectiveness for shaving. A blade of this character can be employed in or as a part of a razor of the open-blade type, which will then have the protective quality of a safety razor although lackinga guari considered as a part distinct from or supplementary to the blade itself, or such a blade can be employed in a razor of any design in which a guard for the cutting edge is provided. In the latter case the razor will have an which is advantageous in the case of safety razors having blades which are adjustable to vary the exposure of the blade edge. My blade also has the advantage, when used in a razor of any of the types having detachable or interchangeable blades,- that it is not-liable to cut any one who may handle the detached blade during its period of use or after it has been discarded.

A blade embodying m invention is characterized by having its s aving edge provided with a series of alternating sharp an dull portions of limited extent, of which the dull portions are located near enough together to prevent the sharp portions from entering the skin of the user when the blade edge is which ting them to reach the beard in the act of shaving. I have found that in spite of the presence of the dull portions aclean and comfortable shave can be readily obtained additional element of safety presented to the skin at an angle at' the skin could be cut, whi e'permit- OF BROOKLINE, MASSACHUSETTS, ASSIGNOB TO GILLETTE SAFETY RAZOR COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION 01' RAZOR.

1924. Serial 110. 711,870.

the accompanying drawing, which shows the parts considerably enlarged as compared with their natural size and in which- Figure 1 is a side elevation of a portion of the blade, and

Figure 2 is a transverse section on the line 2-2'in Figure 1.

In the drawin 2 indicates a portion of, a razor blade o l? which the shaving. edge comprises a series of straight cutting portions 3 alternating witlrnoneutting portions 4 which are integral with the blade and preferably projectslightly beyond the cutting portion 3. This edge formation may be produced by first providing the blade 2 wit 1 then grinding away'limited areas at sep-' 1 arated points to form the cutting portions 3, leavin the intermediate portions 4 unsharpened. It is desirable to form the cut ting portions 3 by means of two similar bevels, so that their sharp edges will be equidistant from the sides of the portions 4 and will therefore be equally protected thereby on both sides of the blade, and unless the blade itself is very thin it is also desirable to bevel the sides of the dull por tions 4, as shown in Figure 2.

In using the blade above described the spaced arrangement of the dull. portions enables the cutting portions to reach the beard when the blade is applied to the skin at a suitable shaving angle, but the skin is either while protected *against being cut ulation of the shaving .or during the mani from the cutting portions by means of the dull portions acting in conjunction with' the natural firmness and elasticity of the skin itself and the flesh beneath it. The dull portions also serve to stretch the skin slightly, the beard.

The dimensions of the sharp and dull portions of'a blade edge embodying my invention' may be varied within considerable limits, sired. This will depend primarily upon the ratio betweenthe width of the spaces between the dull portions and the distance between the .lines in which the sharp portions a thin and smooth but dull edge and (1 blade, if detachable, by bemg held away thereby facilitating the removal of according to the factor of safety deand the to s of the dull portions lie, but it willalso epend to some extent upon the lirmness and elasticity of the skin and flesh of the user. In practise the blade edge should have a factor of safety sullicient to render it usable by persons with thin skins and soft flesh, since in the case of others the cutting portions can be caused to act upon the heard by increasing the pressure of application. The dull portions are preferably made as short in the direction of their len th as is practicable, in order to give the blade a maximum amount of cutting edge, and they should of course be made thin enou h to enable the sharp portions to reach the shin when the blade is applied at a suitable shaving angle.

I claim:-

1. A razor blade provided at its shaving edges with a series of alternating sharp and dull portions of limited extent, the dull portions being integral with the blade and being so proportioned and spaced as to permit the sharp portions to engage the heard but prevent them from cutting the user.

2. A razor blade provided at its shaving edges with a series of integral dull portions having thin rounded edges and separated by sharp portions defined by bevels formed on both sides of the blade between the dull portions.

Signed at Boston, Massachusetts, this second day of June, 1924.

RALPH E. THOMPSON. 

